1. Field of the Invention
The present invention relates to a torque wrench, and more particularly to a torque wrench having a stably guiding member provided for stably guiding an elongated driving shank to rotate or to move within a tubular handle, and for preventing the elongated driving shank from being tilted or swung or vibrated relative to the tubular handle.
2. Description of the Prior Art
Various kinds of typical torque wrenches have been developed and comprise an elongated shank rotatably or pivotally engaged in a tubular handle, and a predetermined or selectively variable torque applied onto the shank by a spring biasing member and/or a spherical coupling member, to effect pivotal movement of the handle and to create an audible indication to the operator when the predetermined or selectively variable torque is applied onto a torque transfer axis of the shank and the handle.
For example, U.S. Pat. No. 4,467,678 to Lindholm discloses one of the typical torque wrenches comprising a spherical coupling member attached to a free end of an elongated shank and engageable into a recess of a spring biased follower which is urged against the spherical coupling member so as to maintain the spherical coupling member within the recess of the spring biased follower by a coil compression spring.
However, the free end of the elongated shank is not limited to rotate or to move relative to the handle and may thus move toward various directions, and may thus be tilted or swung or vibrated relative to the tubular handle.
U.S. Pat. No. 4,870,879 to Shieh discloses another typical torque wrench comprising a shank pin attached to a free end of a ratchet arm and engageable with a rotatable roller that is attached to a spring biased sleeve which will urge the roller against the shank pin so as to create an audible indication to the operator when the predetermined or selectively variable torque is applied onto a torque transfer axis of the ratchet arm and an outer housing.
A screw is threaded to the ratchet arm, to adjust the moving range of the free end of the ratchet arm relative to the outer housing. However, similarly, the free end of the elongated ratchet arm is not limited to rotate or to move relative to the outer housing and may thus also move toward various directions, and may thus be tilted or swung or vibrated relative to the outer housing.
U.S. Pat. No. 5,497,682 to Hsu discloses a further typical torque wrench comprising a parallelepiped connector engaged into a recess of a knocker and engageable into another recess of a shank. However, the recesses of the knocker and the shank are also parallelepiped or include a non-circular cross section, such that the connector may not be easily disengaged from the knocker or the shank.
Similarly, the knocker is also not limited to rotate or to move relative to an outer casing and may thus also move toward various directions, and may thus be tilted or swung or vibrated relative to the outer casing.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional torque wrenches.